The present invention relates to an information retrieval apparatus for retrieving, on the basis of retrieval conditions, primary information registered together with such secondary information which can provide the retrieval conditions when retrieval is required.
A conventional retrieval apparatus of this type includes a CPU (central processing unit), a register unit for entry of primary information together with relevant secondary information, an input device for inputting data such as retrieval conditions, etc., and a display unit which displays a list or the like of pieces of secondary information searched on the basis of retrieval conditions inputted by the input device and which performs the following steps of retrieval operation according to a flow chart as shown in FIG. 22.
At step S1, initialization is executed for the display of lists, etc.
At step S2, retrieval condition setting is executed to set conditions for retrieval of primary information.
At step S3, retrieval is executed on the basis of the retrieval conditions set at step S2.
At step S4, a secondary information list conforming to the retrieval conditions is displayed on the display unit.
At step S5, a specified piece of secondary information is selected for input from the secondary information list displayed on the display unit. Thereupon, primary information with the inputted secondary information is selected and displayed on the display unit.
Now, in conjunction with the above procedure, a subroutine for setting retrieval conditions at aforesaid step S2 will be explained according to a flow chart given in FIG. 23.
At step S21, the next operation to be executed is specified as either setting of contents for retrieval items or operation ending. For this purpose, a cursor is moved to a desired position, either the "END" or "SEARCH ITEMS" position on the retrieval condition setting screen on display to input "END" or "SEARCH ITEMS".
At step S22, it is determined whether or not the input at step S21 is "END". If YES, the retrieval condition setting operation is terminated and the program returns to the main routine of FIG. 22; otherwise, the program proceeds to step S23.
At step S23, the contents of "SEARCH ITEMS" inputted at step S21 are set at given positions on the display, and then the program returns to step S21.
However, the above described prior art information retrieval apparatus has a difficulty in that since a secondary information list is displayed on the display unit after a secondary information retrieval is carried out on the basis of retrieval conditions set at step S2, there may be cases in which when, after a primary information retrieval is made, it is necessary to retrieve the same primary information again. If retrieval conditions different in part from those previously applied, are inputted by an operator who may have forgotten the previously applied conditions, the previously considered primary information can not be it will result that primary information identical with obtained. Another difficulty is that various retrieval conditions previously applied have to be inputted again when such repetition of retrieval is required, which is very troublesome indeed.